JP7093784B2 - Manufacturing method of cutting inserts, cutting tools and cutting materials - Google Patents

Description

Cross-reference of related applications

This application claims the priority of Japanese Patent Application No. 2017-186254 filed on September 27, 2017, and the entire disclosure of further applications is incorporated herein by reference.

This aspect relates to a method for manufacturing a cutting insert, a cutting tool, and a cutting object. More specifically, the present invention relates to a method for manufacturing a cutting insert, a cutting tool and a cutting work piece used for a turning tool.

The cutting tools described in International Publication 2016/043127 (Patent Document 1) and Jikkenhei 2-43105 (Patent Document 2) are cutting tools used for cutting a work material such as metal. In the cutting insert (insert) in the cutting tool described in Patent Document 1, a negative land (land surface) is formed along the straight cutting edge ridge line and the cutting edge ridge line of the nose R.

The cutting inserts of the present disclosure include a first surface having a first corner and a first side extending from the first corner, a second surface located on the opposite side of the first surface, the first surface and the above. It has a third surface located between the second surfaces. Further, the cutting insert has a land surface that is positioned at an angle with respect to the first surface and the third surface between the first surface and the third surface. The land surface is adjacent to the first land surface located along the first corner, the second land surface located along the first side, the second land surface, and the second land surface. It has a third land surface located farther from the first land surface. When the center of the first surface and the axis passing through the center of the second surface are taken as the central axis, the third land surface has a concave shape in a cross section orthogonal to the central axis, and the first land surface on the land surface has a concave shape. It is located farthest from the first corner among the portions located along one side, and is an end portion on the land surface on the side of the first side.

It is a perspective view which shows one cutting insert of the Embodiment of this disclosure. It is a front view which looked at the cutting insert shown in FIG. 1 from the side of the 1st surface. It is an enlarged view which shows the region A1 in FIG. It is an enlarged view which shows the region A2 in FIG. FIG. 3 is a side view of the cutting insert shown in FIG. 2 as viewed from the B1 direction. It is an enlarged view which shows the region A3 in FIG. It is a conceptual diagram when the cutting process is performed using the cutting insert shown in FIG. 1. It is sectional drawing which shows the cross-section of XIII-XIII in FIG. It is sectional drawing which shows the IX-IX cross section in FIG. It is sectional drawing which shows the XX cross section in FIG. FIG. 5 is a cross-sectional view showing a cross section of XI-XI in FIG. It is sectional drawing which shows the cross section of XII-XII in FIG. It is sectional drawing of one cutting insert of an embodiment. It is a side view which shows the cutting tool of embodiment of this disclosure. It is a figure which showed one step in the manufacturing method of the cut product of the embodiment of this disclosure. It is a figure which showed one step in the manufacturing method of the cut product of the embodiment of this disclosure. It is a figure which showed one step in the manufacturing method of the cut product of the embodiment of this disclosure.

<Cutting insert>
Hereinafter, a plurality of embodiments of the cutting insert 1 (hereinafter, also simply referred to as the insert 1) will be described in detail with reference to the drawings. However, in each figure referred to below, for convenience of explanation, only the main members necessary for explaining the insert 1 of the embodiment are simplified and shown. Accordingly, the insert 1 of the present disclosure may comprise any component not shown in each referenced figure. Further, the dimensions of the members in each drawing do not faithfully represent the dimensions of the actual constituent members, the dimensional ratio of each member, and the like.

As shown in FIG. 1, one insert 1 of the embodiment includes a first surface 7, a second surface 9, and a third surface 11. The first surface 7 is the upper surface in FIG. The first surface 7 may include a first corner 3 and a first side 5a extending from the first corner 3. The second surface 9 is the lower surface in FIG. The second surface 9 is located on the opposite side of the first surface 7. The third surface 11 is a side surface in FIG. The third surface 11 is located between the first surface 7 and the second surface 9.

The first surface 7 has a polygonal shape, and in the example shown in FIG. 2, the first surface 7 has a rhombus shape. Therefore, the first surface 7 has four corners and four sides. Further, since the first surface 7 is a rhombus, the third surface 11 has four plane regions.

In FIG. 2, the first corner 3 is one of the four corners of the first surface 7. Further, the first side 5a is one of the four sides of the first surface 7. The axis passing through the center of the first surface 7 and the center of the second surface 9 is defined as the central axis P.

The first surface 7 may have a substantially polygonal shape, and does not have to be a polygonal shape in a strict sense. That is, the side of the first surface 7 of the polygonal shape does not have to be strictly a straight line shape, and may be, for example, a convex curve shape or a concave curve shape. Further, the corner of the first surface 7 of the polygonal shape is not limited to the configuration in which two straight lines intersect, and may be, for example, a shape rounded outward. In the example shown in FIGS. 3 and 4, the first corner 3 has a convex curve shape.

The shape of the first surface 7 is not limited to the above configuration. For example, there is no problem even if the first surface 7 is not a quadrangle but a pentagon, a hexagon, or an octagon.

The size of the insert 1 is not particularly limited. For example, in the embodiment, the length of one side of the first surface 7 may be set to about 3 to 20 mm. Further, the height from the first surface 7 to the second surface 9 can be set to about 5 to 20 mm.

Further, the insert 1 may have a hole 39 that opens on the first surface 7. The hole 39 may penetrate to the second surface 9 located on the opposite side of the first surface 7. In the example shown in FIG. 1, the axis passing through the center of the hole 39 coincides with the central axis P. Further, the hole 39 is not limited to the above-mentioned form, and may be opened to, for example, the third surface 11, from the plane region of one of the third surfaces 11 to the opposite side of this plane region. It may penetrate into another plane area where it is located.

The hole 39 may be used as an insertion hole for a fixative when the insert 1 is mounted on the holder. Examples of fixtures include screws, clamp members, wedges and the like. Further, the insert 1 may be fixed to the holder using a brazing material.

The insert 1 of the embodiment has a land surface 13 located between the first surface 7 and the third surface 11. The land surface 13 in the example shown in FIGS. 5 and 6 is inclined with respect to the first surface 7 and the third surface 11, respectively.

The land surface 13 has a first land surface 15, a second land surface 17, and a third land surface 19. The first land surface 17 is located along the first corner 3. The second land surface 17 is located along the first side 5a. The third land surface 17 is adjacent to the second land surface 17 and is located farther from the first land surface 15 than the second land surface 17. The third land surface 17 has a concave shape.

The land surface 13 is generally called a land and is a narrow flat surface extending along the cutting edge. When the insert 1 has the land surface 13, the durability of the cutting edge is high. In the present disclosure, "along" means a state in which two objects extend substantially in parallel with each other. At this time, the two objects may be in contact with each other or may be separated from each other.

The third land surface 19 may be connected to the second land surface 17. Specifically, the second land surface 17 has a first end portion close to the first land surface 15 and a second end portion located on the opposite side of the first end portion, and the third land surface has a third land surface. 19 may be connected to the second end.

In the example shown in FIG. 4, the first corner 3 has a convex curve shape protruding outward from the insert 1, and the first land surface 15 is located along the first corner 3. The first side 5a has a linear shape, and the second land surface 17 is located along the first side 5a. The third land surface 19 has a concave shape recessed inward of the insert 1. Like the second land surface 17, the third land surface 19 may be located along the first side 5a.

In the present disclosure, "the third land surface 19 has a concave shape" means that the shape satisfies at least one of the following two conditions. First, when the first surface 7 is viewed from the front, the intersection (ridge line) of the first surface 7 and the third land surface 19 is concave. Second, the third land surface 19 in the cross section orthogonal to the central axis P has a concave shape.

The insert 1 may have a cutting edge located at least part of the intersection of the land surface 13 and the third surface 11. When the cutting edge is located at the above-mentioned location, at least a part of the first surface 7 may be the rake surface region 7a. In the example shown in FIG. 3, the region along the land surface 13 on the first surface 7 is the rake surface region 7a.

Further, at least a part of the third surface 11 may be a flank region 11a. In the example shown in FIG. 3, the region along the land surface 13 on the third surface 11 is the flank region 11a.

The cutting edge may have a first cutting edge 23, a second cutting edge 25, and a third cutting edge 27. The first cutting edge 23 is located at the intersection of the first land surface 15 and the third surface 11. The second cutting edge 25 is located at the intersection of the second land surface 17 and the third surface 11. Further, the third cutting edge 27 is located at the intersection of the third land surface 19 and the third surface 11.

Chips generated by the cutting edge during cutting of the work material tend to bend gently while extending in a spiral shape. At this time, since the insert 1 of the embodiment has the above configuration, when the chips come into contact with the third land surface 19, the third land surface 19 tends to function as a guide for the chips. Therefore, the insert 1 of the embodiment tends to discharge chips in the feeding direction of the cutting tool. In other words, it is difficult for chips to move toward the machined surface of the work material. Therefore, the machined surface is not easily scratched. Therefore, the insert 1 of the embodiment provides a good machined surface.

Specifically, as shown in FIG. 7, for example, chips generated by the first cutting edge 23 are easily guided by the third land surface 19. Therefore, the chips tend to flow in the F2 direction, which is the feeding direction of the cutting tool, instead of the F1 direction toward the finished surface. Therefore, the insert 1 has good chip evacuation property, and the machined surface is not easily damaged by chips.

Further, in the example shown in FIG. 8, which is a cross section orthogonal to the first corner 3, the first land surface 15 is inclined with respect to the first surface 7 and the third surface 11 and has a linear shape. The straight line shape does not have to be a strict straight line, and is, for example, 1/10 of the width W1 of the first land surface 15 when the first surface 7 is viewed from the front to an unavoidable degree in manufacturing (for example, when the first surface 7 is viewed from the front). It may have a minute concave shape or a convex shape (below).

When the first surface 7 is viewed from the front, the width W1 of the first land surface 15 in the direction orthogonal to the first corner 3 can be set to, for example, about 0.01 to 0.5 mm. The width W1 may be evaluated in a cross section orthogonal to the first corner 3. For example, FIG. 8 shows the width W1. The width W1 is the distance between the straight line passing through the first corner 3 and parallel to the central axis P and the straight line passing through the first cutting edge 23 and parallel to the central axis P in the cross section as shown in FIG.

The width W1 of the first land surface 15 may be substantially constant from the first end Q1 (the left end in FIG. 4) to the second end Q2 (the right end in FIG. 4) of the first corner 3. Also, it may change from the first end to the second end.

For example, the width W1 may be narrowed from the central portion of the first land surface 15 toward the first end Q1 and the second end Q2. Further, the width W1 may be widened from the central portion of the first land surface 15 toward the first end Q1 and the second end Q2.

Further, in the example shown in FIG. 9, which is a cross section orthogonal to the first side 5a, the second land surface 17 is inclined with respect to the first surface 7 and the third surface 11 and has a linear shape. Similarly to the first land surface 15, the second land surface 17 does not have to be a straight line in the cross section shown in FIG.

When the first surface 7 is viewed from the front, the width W2 of the second land surface 17 in the direction orthogonal to the first side 5a can be set to, for example, about 0.01 to 0.5 mm. The width W2 may be evaluated in a cross section orthogonal to the first side 5a. For example, FIG. 9 shows the width W2. The width W2 is the distance between the straight line passing through the first side 5a and parallel to the central axis P and the straight line passing through the second cutting edge 25 and parallel to the central axis P in the cross section as shown in FIG.

The width W2 of the second land surface 17 is the portion R2 closest to the first corner 3 (the diagonally lower left end in FIG. 4) and the farthest from the first corner 3 (the diagonally upper right upper side in FIG. 4). It may be substantially constant toward the end), or it may be changed.

For example, the width W2 may be the widest or the narrowest in the portion R1 of the second land surface 17 closest to the first corner 3. Further, the width W2 may be the widest or the width W2 may be the narrowest in the portion R2 of the second land surface 17 farthest from the first corner 3.

The third land surface 19 in the example shown in FIG. 10 is inclined with respect to the first surface 7 and the third surface 11. Further, the third land surface 19 has a concave shape recessed inward in the insert 1 in a cross section orthogonal to the first side 5a. As an example shown in FIG. 10, the third land surface 19 may have a curved shape in a cross section orthogonal to the first side 5a. When the third land surface 19 has a concave curved shape in the above cross section, chips can easily flow smoothly through the third land surface 19. Therefore, clogging of chips is suppressed, and the dischargeability of chips is improved.

FIG. 11 is a cross section orthogonal to the central axis P. The third land surface 19 in the example shown in FIG. 11 has a concave shape recessed inward of the insert 1. At this time, the concave shape of the third land surface 19 may be a curved surface shape. For example, as in the example shown in FIG. 11, the third land surface 19 has a curved shape in a cross section orthogonal to the central axis P.

When the third land surface 19 has a curved surface shape in the cross section orthogonal to the central axis P, the durability of the third land surface 19 is high. Therefore, cracks are unlikely to occur on the third land surface 19. In particular, in the above cross section, when the curved shape of the third land surface 19 is an arc shape, the durability of the third land surface 19 is further high.

When the first surface 7 is viewed from the front, the maximum value of the width W3 of the third land surface 19 in the direction orthogonal to the first side 5a can be set to, for example, about 0.01 to 0.5 mm. In the example shown in FIG. 4, the width W3 of the third land surface 19 becomes narrower as the distance from the second land surface 17 increases.

The width W3 may be evaluated in a cross section orthogonal to the first side 5a. For example, FIG. 10 shows the width W3. The width W3 is the distance between the straight line passing through the first side 5a and parallel to the central axis P and the straight line passing through the third cutting edge 27 and parallel to the central axis P in the cross section as shown in FIG.

When the first surface 7 is viewed from the front, the width W3 of the third land surface 19 in the direction orthogonal to the first side 5a on the third land surface 19 is orthogonal to the first side 5a on the second land surface 17. It may have a portion larger than the width W2 in the direction.

In other words, the maximum value of the width W3 may be larger than the maximum value of the width W2 when the first surface 7 is viewed from the front. When the third land surface 19 has the above configuration, chips can be better guided on the third land surface 19. Therefore, the direction in which the chips flow is more stable.

Further, the land surface 13 may further have a fourth land surface 21. The fourth land surface 21 may be located between the first land surface 15 and the second land surface 17 and may have a concave shape recessed inward of the insert 1. The fourth land surface 21 in the example shown in FIG. 4 is located along the vicinity of the boundary between the first corner 3 and the first side 5a at the intersection of the first surface 7 and the land surface 13.

In the present disclosure, "the fourth land surface 21 has a concave shape" means that the shape satisfies at least one of the following two conditions. First, when the first surface 7 is viewed from the front, the intersection of the first surface 7 and the fourth land surface 21 has a concave shape. Second, the fourth land surface 21 in the cross section orthogonal to the central axis P has a concave shape.

When the land surface 13 has the fourth land surface 21 described above, a better machined surface can be easily obtained. The chips generated by the first cutting edge 23 are guided by the fourth land surface 21 and are easily discharged in the feeding direction of the cutting tool, and the chips are less likely to advance toward the machined surface of the work material. Therefore, the machined surface is not easily scratched.

As shown in FIG. 4, when the first surface 7 is viewed from the front, the intersection of the first surface 7 and the fourth land surface 21 is a concave shape recessed inward of the insert 1. Further, the fourth land surface 21 in the example shown in FIG. 11 has a concave shape recessed inward in the insert 1 in a cross section orthogonal to the central axis P.

The concave shape recessed inward of the insert 1 of the fourth land surface 21 may be a curved surface shape. As an example shown in FIG. 11, the fourth land surface 21 may have a curved shape in a cross section orthogonal to the central axis P of the hole 39. When the concave shape of the fourth land surface 21 is a curved surface shape, cracks are less likely to occur on the fourth land surface 21, and the durability of the fourth land surface 21 is enhanced.

Further, as in the example shown in FIG. 12, the fourth land surface 21 may have a linear shape in a cross section orthogonal to the intersection of the first surface 7 and the land surface 13, and as in the example shown in FIG. In addition, it may have a curved shape. When the fourth land surface 21 has a concave curved shape in the above cross section, chips can easily flow smoothly on the fourth land surface 21. Therefore, clogging of chips is suppressed, and the dischargeability of chips is improved. Further, in the above cross section, the curved shape of the fourth land surface 21 may be an arc shape. Note that FIG. 13 is a cross-sectional view corresponding to the cross-sectional view shown in FIG. 12 in the insert 1 shown in FIG. 1 in one insert 1 of the embodiment.

When the first surface 7 is viewed from the front, the width of the fourth land surface 21 in the direction orthogonal to the intersection of the third surface 11 and the second land surface 17 is W4. At this time, the width W4 may have a portion larger than the width W2.

In other words, the maximum value of the width W4 may be larger than the maximum value of the width W2 when the first surface 7 is viewed from the front. When the fourth land surface 21 has the above configuration, chips can be better guided on the fourth land surface 21. Therefore, chips can be stably discharged in the feeding direction of the cutting tool. Therefore, it is difficult for chips to advance to the machined surface of the work material, and the machined surface is less likely to be damaged, so that a good machined surface can be obtained.

FIG. 12 is a cross section orthogonal to the intersection of the first surface 7 and the land surface 13, that is, the first side 5a. The width W4 may be evaluated in a cross section orthogonal to the first side 5a. For example, FIG. 12 shows the width W4. The width W4 is the distance between the straight line passing through the first side 5a and parallel to the central axis P and the straight line passing through the second cutting edge 25 and parallel to the central axis P.

As shown in FIG. 3, the first surface 7 may further have a second side 5b extending from the first corner 3. Further, the land surface 13 may further have a fifth land surface 29 and a sixth land surface 31. The fifth land surface 29 is located along the second side 5b. The sixth land surface 31 is adjacent to the fifth land surface 29 and is located farther from the first land surface 15 than the fifth land surface 29. The sixth land surface 31 has a concave shape. At this time, the intersection of the 5th land surface 29 and the 6th land surface 31 and the 3rd surface 11 is also a part of the cutting edge.

The fifth land surface 29 has the same configuration as the second land surface 17 described above. Further, the sixth land surface 31 has the same configuration as the third land surface 19. Therefore, the fifth land surface 29 can have the same effect as the second land surface 17. Further, the sixth land surface 31 can exert the same effect as the third land surface 19.

Further, in the example shown in FIG. 4, when the first surface 7 is viewed from the front, the second land surface 17 and the third land surface 19 and the fifth land surface 29 and the sixth land surface 31 are the first. It is axisymmetric with respect to the bisector of the corner 3. When the land surface 13 has the above configuration, it can be used with any so-called right-handed or left-handed cutting tool. Therefore, the insert 1 in the embodiment is excellent in economy.

Further, the land surface 13 may further have a concave seventh land surface 33 located between the first land surface 15 and the fifth land surface 29. The seventh land surface 33 in the example shown in FIG. 4 has the same configuration as the fourth land surface 21.

When the land surface 13 has the 5th land surface 29, the 6th land surface 31, and the 7th land surface 33, the 5th land surface 29, the 6th land surface 31, and the 7th land surface 33 are present. , The second land surface 17, the third land surface 19, and the fourth land surface 21 do not necessarily have to be line-symmetrical with respect to the bisector of the first corner 3.

Examples of the material of the insert 1 include cemented carbide, cermet, ceramics, PCD (polycrystal diamond) and cBN (cubic boron nitride).

Examples of the composition of the cemented carbide include WC (tungsten carbide) -Co, WC-TiC (titanium carbide) -Co and WC-TiC-TaC (tantalum carbide) -Co. Here, WC, TiC and TaC are hard particles, and Co is a bonded phase. Cermet is a sintered composite material in which a metal is composited with a ceramic component. Specifically, examples of the cermet include compounds containing TiC or TiN (titanium nitride) as a main component. The material of the insert 1 is not limited to these.

Further, the insert 1 may be composed of only one member made of the material exemplified above, or may be composed of a plurality of members made of the material exemplified above.

For example, as shown in FIG. 1, the insert 1 may be composed of a main body portion 35 and a cutting portion 37, and may have a polygonal plate shape as a whole. The main body portion 35 has a substantially polygonal plate shape, and has a notched portion at a part of the corner. The cutting portion 37 is joined to the notched portion by using a brazing material or the like. Here, in the example shown in FIG. 1, the first corner 3 and the first side 5a are located at the cutting portion 37. In addition, in order to facilitate visual understanding, hatching by diagonal lines is added to the portion of the cutting portion 37 in FIG. 1.

When a material having a relatively high hardness such as PCD and cBN is used as the material of the cutting portion 37 and a cemented carbide, cermet or ceramics is used as the material of the main body portion 35, the insert 1 is used. Although it can be manufactured at low cost, the insert 1 has high durability against a cutting load. The hardness of the main body portion 35 and the cutting portion 37 may be evaluated by measuring the Vickers hardness of each portion.

Further, the insert 1 may be composed of only the main body portion 35 and the cutting portion 37 described above, but for example, in addition to the portions of the main body portion 35 and the cutting portion 37, a coating layer covering the surface of these portions. (Not shown) may be provided. The coating layer may cover the entire surface of the substrate composed of the main body portion 35 and the cutting portion 37, or may cover only a part of the surface of the substrate.

Examples of the material of the coating layer include aluminum oxide (alumina), and carbides, nitrides, oxides, carbon oxides, nitrides, carbonitrides, and carbon dioxide oxides of titanium. The coating layer may contain only one of the above materials, or may contain a plurality of the above materials.

Further, the covering layer may be composed of only one layer, or may be a structure in which a plurality of layers are laminated. The material of the coating layer is not limited to these. The coating layer can be located on the substrate, for example by using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method.

<Cutting tool>
Next, the cutting tool 101 of the embodiment will be described with reference to the drawings.

As shown in FIG. 14, one cutting tool 101 of the embodiment includes a holder 105 having a pocket 103 (insert pocket) on the tip end side, and the above-mentioned insert 1 located in the pocket 103. In one cutting tool 101 of the embodiment, the insert 1 is mounted so that at least a part of the cutting edge protrudes from the tip of the holder 105.

The holder 105 has an elongated rod shape. One pocket 103 is provided on the tip end side of the holder 105. The pocket 103 is a portion to which the insert 1 is mounted and is open to the tip surface of the holder 105. At this time, since the pocket 103 is also open to the side surface of the holder 105, the insert 1 can be easily mounted. Specifically, the pocket 103 has a seating surface parallel to the lower surface of the holder 105 and a restraining side surface inclined with respect to the seating surface.

The insert 1 is located in the pocket 103. At this time, the lower surface of the insert 1 may be in direct contact with the pocket 103, or the sheet may be sandwiched between the insert 1 and the pocket 103.

The insert 1 is mounted so that the cutting edge protrudes outward from the holder 105. One insert 1 of the embodiment is attached to the holder 105 by a clamp member 107. That is, the head of the clamp member 107 is pressed against the inner wall of the hole of the insert 1 to restrain the insert 1 in the pocket 103.

As the holder 105, steel, cast iron, or the like can be used. Steel may be used in these members from the viewpoint of increasing the toughness of the holder 105.

In the embodiment, a cutting tool used for so-called turning is exemplified. Examples of the turning process include inner diameter processing, outer diameter processing, and grooving processing. The cutting tool is not limited to the one used for turning. For example, the insert 1 of the above embodiment may be used as a cutting tool used for milling.

<Manufacturing method of machined material>
Next, a method for manufacturing a machined product according to an embodiment of the present invention will be described with reference to the drawings.

The work piece is produced by cutting the work material 201. The method for manufacturing a machined product according to an embodiment includes the following steps. That is,
(1) The process of rotating the work material 201 and
(2) A step of bringing the cutting tool 101 represented by the above embodiment into contact with the rotating work material 201, and
(3) The process of separating the cutting tool 101 from the work material 201,
It is equipped with.

More specifically, first, as shown in FIG. 15, the work material 201 is rotated around the shaft O1 and the cutting tool 101 is relatively close to the work material 201. Next, as shown in FIG. 16, the cutting edge of the cutting tool 101 is brought into contact with the work material 201 to cut the work material 201. Then, as shown in FIG. 17, the cutting tool 101 is relatively far from the work material 201.

In the embodiment, the cutting tool 101 is moved in the Y1 direction in a state where the shaft O1 is fixed and the work material 201 is rotated to bring it closer to the work material 201. Further, in FIG. 16, the cutting edge of the insert 1 is brought into contact with the rotating work material 201 and moved in the X1 direction to cut the work material 201. Further, in FIG. 17, the cutting tool 101 is moved away in the Y2 direction while the work material 201 is rotated.

In the cutting process in the manufacturing method of the embodiment, in each step, the cutting tool 101 is moved to bring the cutting tool 101 into contact with the work material 201, or the cutting tool 101 is separated from the work material 201. However, of course, it is not limited to such a form.

For example, in the step (1), the work material 201 may be brought closer to the cutting tool 101. Similarly, in the step (3), the work material 201 may be moved away from the cutting tool 101. When the cutting process is continued, the process of keeping the work material 201 rotated and bringing the cutting edge of the insert 1 into contact with different parts of the work material 201 may be repeated.

Typical examples of the material of the work material 201 include carbon steel, alloy steel, stainless steel, cast iron, non-ferrous metal and the like.

1 ... Cutting insert (insert)
3 ... 1st corner 5a ... 1st side 5b ... 2nd side 7 ... 1st surface 9 ... 2nd surface 11 ... 3rd surface 13 ... Land surface 15 ... 1st land surface 17 ... 2nd land surface 19 ... 3rd land surface 21 ... 4th land surface 23 ... 1st cutting blade 25 ... 2nd cutting blade 27 ... 3rd Cutting edge 29 ... 5th land surface 31 ... 6th land surface 33 ... 7th land surface 35 ... Main body 37 ... Cutting part 39 ... Hole 101 ... Cutting tool 103 ... Pocket 105 ... Holder 107 ... Clamp member 201 ... Work material P ... Hole center axis W1 ... Width of first land surface W2 ... Width of second land surface W3 ・ ・ ・ Width of the 3rd land surface

Claims (8)

A first surface having a first corner and a first side extending from the first corner, and a first surface.
The second surface located on the opposite side of the first surface and
A third surface located between the first surface and the second surface,
Between the first surface and the third surface, there is a land surface that is positioned at an angle with respect to the first surface and the third surface.
The land surface is
The first land surface located along the first corner and
A second land surface located along the first side and
It has a third land surface adjacent to the second land surface and located farther from the first land surface than the second land surface.
When the axis passing through the center of the first surface and the center of the second surface is used as the central axis, the third land surface has a concave shape in a cross section orthogonal to the central axis .
The third land surface is located farthest from the first corner among the portions of the land surface located along the first side, and is an end portion of the land surface on the side of the first side. Cutting insert. The cutting insert according to claim 1, wherein the third land surface has a concave curved surface shape in a cross section orthogonal to the first side. The cutting insert according to claim 1 or 2, wherein the ridges of the first surface and the third land surface are concave when the first surface is viewed from the front. The land surface further has a fourth land surface located between the first land surface and the second land surface.
The cutting insert according to any one of claims 1 to 3, wherein the fourth land surface has a concave curved surface shape in a cross section orthogonal to the central axis. When the first surface is viewed from the front,
The third land plane according to any one of claims 1 to 4 , wherein the width of the third land plane in a direction orthogonal to the first side of the third land plane becomes narrower as the distance from the second land plane increases. Cutting insert. When the first surface is viewed from the front,
The third land plane has a portion in which the width of the third land plane in a direction orthogonal to the first side is larger than the width of the second land plane in a direction orthogonal to the first side. The cutting insert according to any one of 5 to 5 . A holder with a pocket located on the tip side,
A cutting tool having the cutting insert according to any one of claims 1 to 6 , located in the pocket. The process of rotating the work material and
The step of bringing the cutting tool according to claim 7 into contact with the rotating work material, and
A method for manufacturing a machined product, comprising a step of separating the cutting tool from the work material.

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